Method for communicating in a network

Abstract

The present invention relates to a method for operating a communication system in a network, the system comprising a primary station and at least one secondary station, the primary station comprising a plurality of transmit antennas and the secondary station comprising a plurality of receive antennas, the method comprising the steps of the primary station selecting a first communication scheme among a plurality of communication schemes, the primary station computing a transmission vector on the basis of the first communication scheme, the secondary station computing a reception vector on the basis of a second communication scheme, the second communication scheme being selected among the plurality of communication schemes by the secondary station on the assumption that a predetermined communication scheme is being used by the primary station.

The invention claimed is: 
     
       1. A method for operating a secondary station in a network comprising a primary station and at least one secondary station, the primary station comprising a plurality of transmit antennas and the secondary station comprising a plurality of receive antennas, the method comprising:
 receiving from the primary station, characteristics of a first communication scheme, 
 deriving post-processing coefficients based on the characteristics of the first communication scheme and the observed channel between the transmit antennas and the receive antennas, and 
 estimating a combined channel based on the observed channel between the transmit antennas and the receive antennas and the result of performing post-processing using said post-processing coefficients, 
 determining CSI information assuming characteristics of a second communication scheme and according to the estimated combined channel, and 
 transmitting said CSI information to the primary station. 
 
     
     
       2. The method of  claim 1 , where the first communication scheme is predetermined. 
     
     
       3. The method of  claim 1 , wherein characteristics of the first communication scheme are received by the secondary station from the primary station before performing the post processing. 
     
     
       4. The method of  claim 1 , where the first communication scheme is based on any of the following: SVD (single value decomposition), zero-forcing, and codebook-based pre-coding. 
     
     
       5. The method of  claim 1 , where the controller assembles a CSI (channel state indicator) report that is based on the estimate of the combined channel, and transmits using a transmitter, the CSI report to the primary station. 
     
     
       6. The method of  claim 5 , wherein the CSI includes an indication representative of a complex transfer function matrix between at least one of the plurality of the transmit antennas and at least one of the plurality of receive antennas. 
     
     
       7. The method of  claim 5 , wherein the CSI includes an indication representative of a right singular vector computed from the SVD (singular value decomposition) of the channel transfer function. 
     
     
       8. The method of  claim 5 , where the receiver is configured to receive from the primary station, data using pre-coding derived from the reported CSI. 
     
     
       9. The method of  claim 1 , wherein the reception occurs on a plurality of spatial streams, the number of spatial streams being predetermined under the assumption of one of either the first or the second communication schemes. 
     
     
       10. The method of  claim 1 , wherein the reception occurs on a plurality of spatial streams, wherein the receiver is configured to receive from the primary station, a number of spatial streams to be used. 
     
     
       11. The method of  claim 1 , wherein the post processing comprises computing a reception vector and the combined channel is estimated based on the product for the actual channel and the reception vector. 
     
     
       12. A secondary station comprising:
 a receiver configured to receive, from the primary station, coefficients used in post processing, 
 a controller configured to select a first communication scheme from a plurality of communication schemes, 
 the controller being configured to derive post-processing coefficients based on the characteristics of the first communication scheme and the observed channel between the transmit antennas and the receive antennas, 
 the controller being configured to estimate a combined channel based on an observed channel between the plurality of transmit antennas and the plurality of receive antennas, and the results of the post-processing using said post processing coefficients 
 the controller being configured to assemble a CSI (Channel State Information) report assuming characteristics of a second communication scheme and according to the estimated combined channel and, 
 a transmitter configured to transmit the CSI report to the primary station. 
 
     
     
       13. The secondary station of  claim 12 , where the results of post-processing are post-processed characteristics and the estimate is the product of the actual channel and coefficients determined by post-processing. 
     
     
       14. The secondary station of  claim 12 , where the first communication scheme is predetermined. 
     
     
       15. The secondary station of  claim 12 , wherein characteristics of the first communication scheme are received by the secondary station from the primary station before the post-processing. 
     
     
       16. The secondary station of  claim 12 , where the first communication scheme is based on any of the following: SVD (single value decomposition), zero-forcing, and codebook-based pre-coding. 
     
     
       17. The secondary station of  claim 12 , where the transmitter is configured to transmit an estimate of the combined channel in a CSI (channel state indicator) to the primary station. 
     
     
       18. The secondary station of  claim 17 , where the CSI includes the channel quality indicator (CQI) which is computed based on an assumption of a primary station using a second communication scheme. 
     
     
       19. The secondary station of  claim 17 , wherein the CSI includes an indication representative of a complex transfer function matrix between at least one of the plurality of the transmit antennas and at least one of the plurality of receive antennas. 
     
     
       20. The secondary station of  claim 17 , where the receiver receives from the primary station, data using pre-coding and derived from the reported CSI. 
     
     
       21. The secondary station of  claim 12 , wherein the transmission and reception each occur on a plurality of spatial streams, the number of spatial streams being predetermined under the assumption of one of either the first or the second communication schemes. 
     
     
       22. The secondary station of  claim 12 , wherein the transmitter is configured to transmit on a plurality of spatial streams and the receiver is configured to receive on a plurality of spatial streams, and wherein the receiver is configured to receive from the primary station a number, the number indicating the number of spatial streams to be used by the transmitter and by the receiver of the secondary station. 
     
     
       23. The secondary station of  claim 12 , wherein the post processing comprises computing a reception vector and the combined channel is estimated based on the product for the actual channel and the reception vector. 
     
     
       24. A method for operating a secondary station in a network comprising a primary station and at least one secondary station, the primary station comprising a plurality of transmit antennas and the secondary station comprising a plurality of receive antennas, the method comprising:
 selecting by a controller of the secondary station, a first communication scheme from among a plurality of communication schemes, 
 using a controller to derive post-processing coefficients based on the characteristics of the first communication scheme and the observed channel between the transmit antennas and the receive antennas, 
 using the controller to estimate a combined channel based on an observed channel between the plurality of transmit antennas and the plurality of receive antennas, and the results of the post-processing using said post processing coefficients 
 using the controller to assemble a CSI (Channel State Information) report assuming characteristics of a second communication scheme and according to the estimated combined channel and 
 transmitting via a transmitter of the secondary station, the CSI report to the primary station. 
 
     
     
       25. The method of  claim 24 , where the results of the post-processing are coefficients determined by the post-processing. 
     
     
       26. The method of  claim 25 , where the first communication scheme is predetermined. 
     
     
       27. The method of  claim 25 , wherein characteristics of the first communication scheme are received by the secondary station from the primary station before performing the post processing. 
     
     
       28. The method of  claim 25 , where the first communication scheme is based on any of the following: SVD (single value decomposition), zero-forcing, and codebook-based pre-coding. 
     
     
       29. The method of  claim 25 , where the controller assembles a CSI (channel state indicator) report that is based on the estimate of the combined channel, and transmits using a transmitter, the CSI report to the primary station. 
     
     
       30. The method of  claim 29 , where the CSI includes the channel quality indicator (CQI) which is computed based on an assumption that the primary station is using a second communication scheme. 
     
     
       31. The method of  claim 29 , wherein the CSI includes an indication representative of a complex transfer function matrix between at least one of the plurality of the transmit antennas and at least one of the plurality of receive antennas. 
     
     
       32. The method of  claim 25 , where the receiver is configured to receive from the primary station, data using pre-coding derived from the reported CSI. 
     
     
       33. The method of  claim 25 , wherein the reception occurs on a plurality of spatial streams, the number of spatial streams being predetermined under the assumption of one of either the first or the second communication schemes. 
     
     
       34. The method of  claim 25 , wherein the reception occurs on a plurality of spatial streams, wherein the receiver is configured to receive from the primary station, a number of spatial streams to be used. 
     
     
       35. A method for operating a secondary station in a network comprising a primary station and at least one secondary station, the primary station comprising a plurality of transmit antennas and the secondary station comprising a plurality of receive antennas, the method comprising:
 receiving from the primary station characteristics of a first communication scheme, 
 estimating a combined channel based on the observed channel between the transmit antennas and the receive antennas and the result of performing post-processing using post processing coefficients signalled from the primary station 
 determining CSI information assuming said characteristics of the first communication scheme and according to the estimated combined channel and 
 transmitting said CSI information to the primary station. 
 
     
     
       36. The method of  claim 35 , where the results of the post-processing are coefficients determined by the post-processing. 
     
     
       37. The method of  claim 35 , where the first communication scheme is predetermined. 
     
     
       38. The method of  claim 35 , wherein characteristics of the first communication scheme are received by the secondary station from the primary station before performing the post processing. 
     
     
       39. The method of  claim 35 , where the first communication scheme is based on any of the following: SVD (single value decomposition), zero-forcing, and codebook-based pre-coding. 
     
     
       40. The method of  claim 35 , where the controller assembles a CSI (channel state indicator) report that is based on the estimate of the combined channel, and transmits using a transmitter, the CSI report to the primary station. 
     
     
       41. The method of  claim 40 , where the CSI includes the channel quality indicator (CQI) which is computed based on an assumption that the primary station is using a second communication scheme. 
     
     
       42. The method of  claim 40 , wherein the CSI includes an indication representative of a complex transfer function matrix between at least one of the plurality of the transmit antennas and at least one of the plurality of receive antennas. 
     
     
       43. The method of  claim 35 , where the receiver is configured to receive from the primary station, data using pre-coding derived from the reported CSI. 
     
     
       44. The method of  claim 35 , wherein the reception occurs on a plurality of spatial streams, the number of spatial streams being predetermined under the assumption of one of either the first or the second communication schemes. 
     
     
       45. The method of  claim 35 , wherein the reception occurs on a plurality of spatial streams, wherein the receiver is configured to receive from the primary station, a number of spatial streams to be used. 
     
     
       46. A method for operating a secondary station in a network comprising a primary station and at least one secondary station, the primary station comprising a plurality of transmit antennas and the secondary station comprising a plurality of receive antennas, the method comprising:
 selecting a first communication scheme from among a plurality of communication schemes, 
 receiving coefficients to be used in post-processing 
 estimating a combined channel based on an observed channel between the plurality of transmit antennas and the plurality of receive antennas, and the results of the post-processing using said post processing coefficients, 
 assembling a CSI (Channel State Information) report assuming characteristics of the first communication scheme and according to the estimated combined channel and 
 transmitting the CSI report to the primary station. 
 
     
     
       47. The method of  claim 46 , where the results of the post-processing are coefficients determined by the post-processing. 
     
     
       48. The method of  claim 46 , where the first communication scheme is predetermined. 
     
     
       49. The method of  claim 46 , wherein characteristics of the first communication scheme are received by the secondary station from the primary station before performing the post processing. 
     
     
       50. The method of  claim 46 , where the first communication scheme is based on any of the following: SVD (single value decomposition), zero-forcing, and codebook-based pre-coding. 
     
     
       51. The method of  claim 46 , where the controller assembles a CSI (channel state indicator) report that is based on the estimate of the combined channel, and transmits using a transmitter, the CSI report to the primary station. 
     
     
       52. The method of  claim 51 , where the CSI includes the channel quality indicator (CQI) which is computed based on an assumption that the primary station is using a second communication scheme. 
     
     
       53. The method of  claim 51 , wherein the CSI includes an indication representative of a complex transfer function matrix between at least one of the plurality of the transmit antennas and at least one of the plurality of receive antennas. 
     
     
       54. The method of  claim 46 , where the receiver is configured to receive from the primary station, data using pre-coding derived from the reported CSI. 
     
     
       55. The method of  claim 46 , wherein the reception occurs on a plurality of spatial streams, the number of spatial streams being predetermined under the assumption of one of either the first or the second communication schemes. 
     
     
       56. The method of  claim 46 , wherein the reception occurs on a plurality of spatial streams, wherein the receiver is configured to receive from the primary station, a number of spatial streams to be used. 
     
     
       57. A secondary station comprising:
 a receiver configured to receive, from the primary station, coefficients used in post processing, 
 a controller configured to select a first communication scheme from a plurality of communication schemes, 
 the controller being configured to receive from the primary station, coefficients to be used in post-processing, 
 the controller being configured to estimate a combined channel based on an observed channel between the plurality of transmit antennas and the plurality of receive antennas, and the results of the post-processing using said post processing coefficients, 
 the controller being configured to assemble a CSI (Channel State Information) report assuming characteristics of the first communication scheme and according to the estimated combined channel, and 
 a transmitter configured to transmit the CSI report to the primary station.